Copying device



June 10, 1947. w. SCHINDLER 2,422,137

COPYING DEVICE Filed Nov. 4, 1943 B YPA J5 VAL If T1 lV.

BYPASS VAL VE Fig.3-

I I 20 e2- 1 I INVE NT OR WERNER SCH/N01. ER

T v T rizmhw m ATTOR NETS Patented June 10, 1947 UNITED STATES PATENT OFFICE Application November 4, 1943, Serial No. 508,982 In Switzerland September 8, 1942 -1 Claim. 1

My invention relates to improvements in copying devices for the operation of automatics, machines and apparatus by photo-electric cells; and the objects of my improvement are, first, to replace the templets used heretofore in such copying processes by a drawingor photo of the work piece to be copied, second, to materially reduce the costs of copying, and third, to speedup the copying process.

Heretofore machine tools and other machines, automatics and apparatus for series work have been mechanically controlled by expensive templets or patterns in connection with the copying process. The manufacture of such templets however, requires much time, great accuracy, and often is too costly for small or middle size series Work.

The inventive idea of my present invention is to replace such templets by an accurate, yet cheap, plan, e. g. a drawing to any chosen scale or a photo of the workpiece to be copied, which is laid upon a photocell or projected thereon by suitable optical means, and the outlines of which are controlled by a light ray thereby automatically controlling the movements of the machine part.

I attain these and related objects by the mechanism and installation illustrated in the accompanying drawing, in which Fig. 1 is a schematic plan of the complete apparatus of the copying device, comprising an electrical and hydraulic transfer mechanism; Fig. 2, the electrical transfer mechanism comprising a servo-motor; Fig. 3, the electrical transfer mechanism adapted as motor-generator aggregate; Fig. 4, a detail of the transfer mechanism comprising an electromagnet acting upon the hydraulic portion; and Fig. 5, an electrically controlled magnet acting directly upon the machine part to be operated.

The source of light produce a lightray undisturbed by the daylight and is fed, together with the amplifier 2, by the electrical net mains N. The photocell 3, which is connected with the amplifier 2 and exposed to the said lightray, may be secured to the cylinder 4 which is freely supported and upon which the operating machine part is mounted. The cylinder 4 and its piston 5 are slidably mounted on or in each other in a longitudinal sense. The piston 5 is anchored at its outer end to a stationary point 6, while the cylinder 4 is movable and is normally urged in one direction by a constant mechanical pressure, produced, for example, by a pressure spring or a counterweight. The cylinder is moved in the opposite direction by hydraulic pressure and by 2 varying this hydraulic pressure, the position of the movable cylinder relative to the piston is changed. In Figure 1 a spring 4a is shown for applying a constant force to the cylinder '4.

The current impulses generated in the photocell, carried over at least one amplifier into the line I I, operate the electrical transfer mechanism e. g. an electrical servo-motor S with forward and backward rotation, the shaft of which may turn in each sense of rotation up to 90 degrees and is coupled with a hydraulic bypass control valve 1. The angular throw of the shaft is adjustable in order to open the bypass valve 1' more or less and thus to regulate the oil quantity fed by the pressure pump 8 into the cylinder 4 for the purpose of displacing the cylinder relative to the stationary piston 5.

The plan ll! of the form of line to be copied is laid upon the photocell 3. or respectively projected thereon, and the cylinder 4 is displaced crossways under the light-source I. When the controlling lightray projects through the plan or drawing in onto the photocell 3, the amplifier 2 is excited, the servo-motor 9 rotated, the bypass control valve 1 opened, the pump 8 delivers'oil into the left hand end of the cylinder 4, and the lattertogether with the machine part to be operatedwill recede from the point of attachment 6 for the piston. When, however the controlling lightray strikes upon the said form of line, it will act less or not at all upon the photocell 3, i. e. the motor 9 rotates backward, the valve 1 is opened less, the pump 8 feeds less oil, and the cylinder 4 is displaced toward the fixed point 6 by virtue of the now prevailing constant mechanical pressure. The movement of the cylinder 4 and of the machine part connected thereto doing the copying work, corresponds to that of the line on the plan which is successively controlled by the lightray.

The device also may comprise a freely movable piston, upon which the photocell and the machine part to be operated are mounted, in which case the cylinder is stationary.

Fig. 2 illustrates another form of mechanical transfer mechanism between the electrical servomotor and the control valve of the hydraulic part. The current impulses generated in the photocell and carried over the amplifier into the lines ll act upon an electrical servo-motor l2 for forward and backward rotation, the pinion I3 of which engages the gear segment [4. The latter is rockably mounted in the shaft [5 and its arm Hi again opens the bypass valve 1 more or less, thereby automatically changing the oil volume of a hydraulic control device, as described above, and automatically controlling the position of the cylinder 4 relative to the piston 5 and thus also the movement of the said machine part. The servomotor is restored to its initial position by the valve 1, this valve being subjected to the action of a restoring spring the pressure of which is increased when the valve opens.

According to Fig. 3, the electrical transfer mechanism also may comprise an electric motor 11 coupled to a dynamo, the housing of which is rotatively mounted. The current impulses car ried from the photocell over the amplifier through the lines I I act upon the exciting winding of the dynamo. The housing of the latter thus is rotated more or less, and the bypass valve 1, which is connected to the transfer member (adapted e. g. as shown as grooved pulley I3), is opened more or less. In this manner the oil volume of a hydraulic control device is changed and, a described above, the motion of the machine part is automatically controlled. The housing 13 is prevented from rotating continuously by the grooved pulley l9 which is coupled with the valve 1. The valve '5 is placed under the action of a restoring spring which tends to restoreit in its closed position; the valve is opened when increasing the traction of the housing; if this traction becomes maller than the restoring pressure of the spring, the housing will be restored by the valve to its initial position. The output of the motor is constant; the housing is rockably supported and prevented from rotating continuously by the valve 1 through the pulley l9. The armature rotating in the housing is coupled with the motor. If the winding of the housing is excited more or less in dependence upon energization of the photo-cell, the housing will rotate more or less, thus opening the valve more or less against the action of therestoring spring thereof. The current supplied by the dynamo varies with the lat ters excitation and could be used for exciting an auxiliary bigger dynamo in order to attain still greater variations of the current impulses.

The further form of electrical transfer mechanism shown in Fig. 4 comprises an electric vertical magnet with the winding 20 and the core 21. The current impulses generated in the photocell 3 and carried over the amplifier 2 into the lines H act upon the winding 20 to attract the core 2| more or less. The bypass valve 1 connected to the latter thus is opened more or less to vary the oil volume of a hydraulic control device. In this way, as described before, the motion of the machine part is automatically controlled.

According to Fig. 5, the copying device also may comprise an electrical transfer mechanism without any hydraulic P rtion. In this case the current impulses, generated in the photocell 3 and carried over the amplifier 2 and through the lines [I into the winding 22 of an electric vertical magnet, act upon the latter to attract its core 23. The latter operates the machine part 24 either directly, or indirectly by displacing the work piece.

The copying device described mainly is suited for milling, grinding, boring, turning and similar machine tool operations for series work.

What I claim and desire to secure by Letters Patent is:

In a copying device, a movable cylinder, a pattern upporting means movable with said cylinder, a stationary piston in said cylinder, a fluid pump, a fluid conduit connecting said pump with said cylinder for supplying pressure fluid thereto, means opposing the pressure fluid, a control valve interposed in said conduit, 2. pattern tracer controlled servo-motor for regulating said valve said servo-motor including a motor-generator aggregate in which a generator housing is rockably supported and means on said housing for actuating said valve, said housing rotating in dependence upon energization of the photo-cell through the armature of the generator coupled with the motor.

WERNER SCHINDLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,172,313 Young Sept. 5, 1939 2,331,337 Meyer Oct. 12, 1943 2,259,472 Johnson Oct. 21, 1941 2,238,717 Cook Apr. 15, 1941 2,226,677 Vikhman Dec. 31, 1940 2,108,025 Shaw Feb. 8, 1938 

